The application of the indoor cameras equipped in smart homes are popular consumer choices. These cameras are used for monitoring babies, guarding the security of doorways, protecting the safety of stove/grills, assisting elders, and for many other functional applications and use scenarios. However, a major concern for the application of the indoor cameras is privacy protection as the output video includes detailed visual data that may contain private information (e.g., unclothed human body). Obviously, to provide more security, an application requires more detailed information from the video data; while to protect privacy, the same application needs to mask certain information in the video data. Therefore, a video monitoring system needs to balance the needs of security requirements and the needs of the privacy requirements.
There are several applications developed to balance such conflicting needs. For example, a small network of extremely low-resolution color sensors is adopted to replace the high-resolution video camera. In another example, only extreme low-resolution videos are used to preserve privacy, which are suitable for certain activity classifications. In such system with heightened privacy preservation in the system designs, however, the loss of detailed information makes many security applications infeasible.